All concrete surfaces are subject to cracking and spalling. Roadways, airport runways, bridge decks, bridge piers, industrial flooring and other heavy-traffic, concrete pavements are all subject to stresses induced by thermal changes, freeze/thaw cycles and especially repeated flexing in response to loading. And although fiber-reinforced concretes are now available (see U.S. Pat. No. 3,429,094) which provide much higher flexural strengths than conventional concrete, the amount of fiber which can be effectively blended with the concrete is limited to about 2 volume percent. Due to this relatively low fiber content and to the fact that it is difficult to mix and consolidate steel fiber reinforced concretes containing even this limited amount of fiber (2 volume percent), flexural strengths attained on steel fiber reinforced concretes produced in the field are limited to the range of 800 to 1200 psi.
When used as an overlay for deteriorated concrete (or other) surfaces, it is desirable that the flexural strength be as high as possible to minimize the formation of cracks and to keep the cracks closely knit once they do form. In considering steel fiber reinforced concretes as overlay materials, both the flexural strength of the concrete and its bond to the substrate controls its performance and longevity. The present invention provides for both substantially improved flexural strength levels to resist cracking and subsequent crack propagation and a novel and superior bonding of the overlay concrete to the substrate material which is being rehabilitated.